Crown adapter



characters o Patented Jan. 30, 1923.

RICHARDSON H. TAYLOR, OF MEEKER, OOLRADO. I

` CROWN ADAPTER.

Application iedctober 1e, 1922. seriai No. 595,544,

To all whom t may concern Be it known that I, RICHARDS@Y at Meeker, inthe county of Rio Blancovand State of Colorado, have invented certainnew and useful Improvementsin Crown Adapters; and I do declare thefollowing to be a full, clear, and exact description vof the invention,such as will enable others skilled in the art to which it appertains tomake and use the same, reference being had to the accom anying drawings,and to the Vreference marked thereon, which form a part of thisspecification.

This invention relates to dental instru` ments and more particularly toan instru ment to be used by dentists in fitting the edge of the crownat the gingiva in a sure and accurate manner.

In dental work it often becomes necessary to apply to a tooth a goldcap, generally referred to as a crown. Crowns for this purpose aresupplied ready made by dental supply houses, and dentists usually carrya number of assorted sizes in stock. y When a tooth is to be crowred, itis ground down l to the required size and its circumference is thenmeasured by an instrument called a dentimeter, one example of which is'described and claimed b me in my copending application 'Serial umber583,187, file d August 21, 1922. Broadly, a dentimeter 1s an instrumentby means of which a loop of soft metal wire, preferably iron, is placedabout the tooth and twisted into a closeA iit. The loop is then removedfrom the tooth and becomes an almost exact measurement of the toothscircumference. A crown is then selected which is slightly smaller insize than the tooth actually requires, and this is stretched to theproper size by means of my improved crown adapter, which I will nowdescribe, reference being had for this purpose to the accompanyingdrawing, in which- Fig. l shows a plan view of my crown adapter, withthe stretching points in spaced position;

Fig. 2 is a view similar to that in Fig. l, but shows the stretchingpoints in closed position;

Fig. 3 is a view looking in the direction of arrow 3 in Fig. 2;

Fig. 4 is a view looking in the direction of the arrow 4 in Fig. l;

Fig. 5 is a fragmentary view showing a TnY-, Lon, a citizen of theUnited States, residing` section of a crown in place on the stretch- F 7is a view looking in the directiony of arrow 7, Fig. 5; `and e Y F ig. 8is a view v showing the manner in which the-dentimeter is used inkadjusting the crown adapter.

The same'reference characters will be used to indicate the same partsthroughout the several views. y. f

Numeral l represents my crown adapt-er as a whole, while 2 and 3represent the two relatively movable members, which are substantiallycircular andare pivotally con-k nected at their centers by means of abolt 4, or yother suitable means. A handle 5 is formed integral with orotherwise rigidly secured to the movable member 3, while a similarhandle member 6 is secured to member 4. A screw'7 passes through one ofthe handles (6) and has itsend so positioned that it will engage theshoulder S on the handle 5 and serve as a'stop by means of which themovement of the handles towards each other can be limited. Secured tothe periphery of the member 2 arek a number of curved,outwardlyprojecting stretching points A, A1, ,A2, A3, A4 and A5, andsecured to corresponding points on the periphery of member 3 areco-operating points B, B1, B2, B3, B14 andB. The points A and Bare soarranged with respect to each other that when the handles 5 and -6 arespread apart as shown in- Fig. 2, .thef points approach each othertothe, position shown in Fig. `3, and when the handles are broughttogether to the position shown in Fig. l, the points move apart to theposition shown in Fig. 4. It is evident that if a ductile band such as acrown or a matrix 9 (Figs. 5 and 7) be placed about any pair of pointswhen they are in the position shown in Figs. 2 and 3 and the handlesmoved to the position shown inFig. l, the movement of the v points tothe position shown in Figsl, 5 and 7 will stretch the band, the amountof stretching being de` points move about a central point, the outersides thereof can onlyl be parallel at a single position. I thereforeconstruct my spread-` ing points so that the circumference is slightly:less at the tips than at the base when they instrument is in theposition shown in Fig. 2, and approximately' equal when the pointshave'moved apart the distance usually found necessary to produce therequiredstretching. The advantage ofi having the spreading points `move,about :r central point and from" anoutwardly/'taper'- ing position to ayarallel osition instead of in'k a constant'yI paral elf position,v as

wenn te the case n they' movd i. fis' that there Cylindrical" straightline, n 4 I p band or ring is placed on the pinsr` to'fbe stretched; themetal will probably yieldy e little more readily if it starts Lat oneAedge and then finally becomes equal for the wholel transverse area.Tlie'slight taper also enablesme tof' Inore readily litE the band onto'the stretching` points. l

The circular 'movement isalso'of great advantage where/it isnecess'aiytov stretch the upper part of the crown'c'lse tothe' top thereoisoastofmake' it larger at5 thetopv than' at'the bottom'.` The crownis',merely` io (ir-ig; e). Tifefioopfiiis thwarted about the* nearestp'airofTA points the manner", shown` in'j 8, the handles are pressed`gently* together4 until thel loop lll becomes taut,` and the ser'ew 7 isadj usted *to this porsin tion. The* adapter is then moved -Tto thelpositionshown inFiQ. 2', and a crownis selected and applied to'- thestretching points', after which the handles are pressed together,

which spreads the pointsland'stretchesthe4 crown to thereq'u'ired size.V

lnorde'r" to accommodate croyvr'isV of' all different: sizes, from `aysmall lower inciso'r to a'flalrge molr'. without materiallyehanglnrin?'g`j tleshapeof the circumference', l prei/iden number" ofpairs of' stretchir'ig@points (sii: pair' shown) of different sizes.

lt'isv` apparent from the above that. yl have produced an instrumentthat will permit dentist to quickly and conveniently stretch acrown to apredetermined size,l and where necessary, to enlarge the upper endthereof to afgreater diameter than the lower.

Having now described my invention, whatl` claim is E l. A crown adaptercomprising two members relatively rotatable i' about' a' co'i'rinionvpivot, a plurality" of pairs of stretchiner members, andmeans" forrotating the mem--k bers.

2. Axcrown adapter having' two members` pivotallyy connected, `a.handlel scour-edito each member, a plurality ofpairs of stretch-H nlepeints, SBfiurd with@ peripheral' @dees one member' oteaclrpairbeingfsecured to;v each pivoted member and adaptedy toV moved: towards or awayfrom each other' as'ftlie members'a're relatively rotatedz'tlcroutA thepivot; and ya stopffor limiting the spread! ing movement' ofv saidpoints.

A' crownadapterxhavingtwo members p'ivotally'connected, ahandle' securedto each* M75 points secured to the peripheraledges,V oneY member, aplurality yofV pairsof stretching member of eachlpair being secured toeach pivo'te'dmernbier and adapted tobe'moted` towardsx or away fromeach other as the members are relatively rotated about' the pivot,andanladjustable stop forA limiting* the sp'readingy movement ofsaid points. h4. A crown adapter consisting'of two flat,

subs'tantially circular members? pi'votally'; connected at; theircenters, a number of stretching points secured lat spaced intervalsabout theperiphery of each member, eachI point on' one memberco-o'perating with a complementary point on the other member` a yhandlesecured to each member whereby they maybe'relatively"rotated, and a"sto'pf" means `secured to ysaid handles`4 for limiting theirj movementto a predetermined amount. In` testimonyy whereof` I allix my signa`ture.

` RICHARDSON H; TAYLOR'.

